Of all the questions asked of writers, one of the most common is, "How autobiographical is your work?" The plain answer must be "in every way" for all books grow from the bones of each writer's life. What kind of temperament the writer has, whether he or she tends towards the rational or the emotional, what kind of relationship the writer had with his or her mother; in essence, everything which makes up the man or the woman also makes up his or her books. The more complicated answer, however, must be, "I no longer remember". If a story or a novel is truly to live, it must wrest itself from its moorings in order to fly. An event from real life, a "true story", will merely lie dead on the page unless it has been exposed to fiction's alchemy, unless it is reremembered, reimagined, let loose into something freer and grander.

"Real life" is a monotonous flat plain, with only the occasional mountain, while fiction is the shapeliest of countries. It is all unexpected mists and oceans, deep wells and horizons, virgin land where no-one has trodden. I remember how shocked I was when some readers read my first novel, Messages From Chaos (about a hopelessly passive woman called Anna Lawrence) as "fact". "But I am not like that," I pleaded to some unseen audience in my head at night, desperate and saddened. Later I laughed when I heard that at least two of my ex-boyfriends were proudly declaring themselves to be the prototype for Anna's boyfriend, the lecherous television journalist Jimmy West. I laughed even harder when the rumour reached me that someone had told someone else that it was actually George Negus (sorry George).

Of course, there were elements of myself in Anna Lawrence, but only elements. Paradoxically, in order for a character to live on the page, he or she must be distilled in some way, as if reduced to pure essence. In other words, I took a part of my own self, annexing entire sub-continents, whole parts of myself which did not fit in. I took certain parts of my friends too, casual remarks overheard, stealing without shame anything which would in the end make something larger than myself, something more emblematic.

Yet to certain readers, none of this matters. To them the closer the character is to the author in age and circumstance, the closer the autobiographical element is reckoned to be. In this sense it was like throwing sand in some reader's eyes when I created Billy Hayes in A Big Life, a tumbling boy whose work was air, who of all my characters is probably closest in temperament to me. I was living in Hong Kong then and hating it, and Billy's story was a metaphor for my own experience of Hong Kong, where writing and the arts in general are regarded as things the world could do without. In Hong Kong, it was as if I was invisible, for I was a writer whose work might as well have been made of air, so meaningless and ephemeral was it regarded in comparison with the real business of making money. But even after I had finished A Big Life, I felt I had not quite finished with Hong Kong. I began to imagine how I could confront the place head-on rather than metaphorically. As well, each book for me is a kind of reaction to the last and after criticism of A Big Life and its plotless meanderings I determined to write a plot-driven book. This was the sole idea with which I started Hungry Ghosts, knowing only that it was to be plot-driven.

Each time I begin writing it is to find out what I am writing about: I found I was writing about the excesses I had witnessed in Hong Kong, the sexual abuse by Western men of Asian women, the way Hong Kong is a Chinese city in which a tiny band of Caucasians live blinded to the people who surround them. I found my loathing of Hong Kong propelling my story: it was where my first marriage ended, where two of my closest friendships faltered, the place where I momentarily imagined I had come to the end of myself. By the time I had created a new first-person character in Rachel Gallagher, I no longer cared if readers would confuse her with myself, so immersed was I in the exhilaration of writing. Without realising it I had entered that virgin, shapely country called fiction and had no choice but to walk on. I did not know until I had finished Hungry Ghosts that it would end up as a tragedy. If its particular details are not my own, its sense of tragedy is, and it is there where my autobiography dwells.